This invention relates to the field of plug-type connectors and, more particularly, relates to small ruggedized plug-type connectors for use in connecting plugs to small electrical devices such as portable radio telephones.
The use of small connectors to connect cords, cables or wires to various electrical devices has been known for many years. In one typical application, such a connector is installed in a portable radio telephone. A plug capable of mating with the connector is affixed to the end of a cord in a cord/plug assembly. Because devices such as radio telephones are designed to be as portable as possible, a device""s size and weight become critical design characteristics. As a result, every component of such a device is designed to help minimize the device""s size and weight. In particular, it is useful for the connectors to have small profiles, sizes and weights.
While a connector is designed to be as small as possible, at the same time, the connector must also meet high durability requirements. For example, a cord/plug assembly is typically inserted into a radio telephone""s connector when the telephone is placed in the xe2x80x9chands-freexe2x80x9d mode of operation. This is done to recharge the battery, to connect the telephone to a speaker, or to perform other functions. When a user moves the telephone while the cord/plug assembly is connected, large amounts of sudden, non-constant, and unpredictable force may be placed on the connection between the plug and the connector. These forces may result in momentary open connections or shorts that may disrupt the operation of the telephone. Further, these forces may inflict damage to the connector, the plug, or both. Thus, it is important for the connector to be robust and durable enough to withstand a wide variety and large amount of forces over the life of the device.
FIG. 1 illustrates one prior art connector. The connector includes a unitary insulative housing molded from plastic. The insulative housing includes a thick plastic shell surrounding a receptacle cavity. A set of electrical contacts extends from within the receptacle cavity toward the open front. An integral mounting flange extends from each end of the housing. Each mounting flange has a central mounting hole through which a fastener may be extended to affix the housing to a printed circuit board. In addition, two metal side plates having downward-extending hold-down tabs are inserted through the bottom of the housing to form the inner side surfaces of the receptacle cavity. In use, the hold-down tabs are inserted through the circuit board and soldered in place. Unfortunately, although the mostly-plastic construction is durable enough to withstand strong forces, the profile of the front of the connector is too large to be used in many devices. Thus, a need exists for a rugged connector with a profile and overall size small enough to meet the design requirements of today""s electrical devices.
FIG. 2 illustrates another prior art connector. The connector includes an insulative housing, a metal shroud, and an electrical contact assembly. The insulative housing includes a central member and two side members. The metal shroud includes a top plate, two side plates, a discontinuous bottom plate and a plurality of mounting and assembly tabs, including a hold-down tab extending downwardly from each side plate. Each side plate further includes an interlock hole. The shroud fits between the central member and the side members of the insulative housing to form a receptacle cavity. The electric contact assembly includes one or more electrical contacts which are inserted into the insulative housing. The shroud is attached to a printed circuit board by inserting the hold-down tabs through corresponding holes in the circuit board and soldering them in place. The insulative housing is held in place against the shroud by the plurality of mounting tabs. In use, a plug is inserted into the receptacle cavity and held there by spring-loaded locking teeth which are biased through interlock holes in the side plates of the shroud. A connector using a metal shroud instead of mostly-plastic construction is much smaller in profile and overall size than a mostly-plastic connector of equal strength. Unfortunately, when the plug is subjected to typical pulling and bending-type forces, those forces are transferred to the metal shroud through the locking teeth, causing the metal shroud to separate from the insulative housing and from the circuit board. When the shroud and housing separate, the plug may separate from the electrical contacts of the connector. More significantly, the solder joints between the hold-down tabs and the circuit board can also fail. When the hold-down tab solder joints fail, the electric contact assembly is held in place only by the solder connections between the individual electrical contacts and the printed circuit board. Additional forces exerted on the connector are then transferred directly to the electrical contacts. In either case, the electrical connection between the electrical device and the plug may be degraded or even completely disabled. Thus, a need exists for a small connector with greater mechanical and electrical durability characteristics.
Therefore, a need exists for a ruggedized miniature electrical connector assembly having a reduced size while at the same time providing enough strength and durability to withstand the rough treatment to which electrical devices such as portable radio telephones are typically subjected.
In accordance with the teachings of the present invention, a small ruggedized plug-type electrical connector assembly comprises an insulative housing, an electrical contact assembly, and a stiffening member. The insulative housing comprises a central member, two side members, and two mounting flanges. The stiffening member comprises a shroud and a pair of mounting flanges. The shroud of the stiffening member fits in between the central member and the side members of the insulative housing, and the mounting flanges of the stiffening member are positioned underneath the mounting flanges of the insulative housing. The electric contact assembly comprises one or more electrical contacts which are inserted into the insulative housing. The mounting flanges of both the insulative housing and the stiffening member are fastened to a printed circuit board in a layered arrangement. Finally, one end of each electrical contact is affixed to a corresponding trace on the circuit board. In operation, a plug is inserted into the connector, and the majority of the forces exerted by the plug on the connector are transferred to the circuit board via the shroud, the stiffening member mounting flanges, and the fasteners. In addition, the stiffening member is held in place against the insulative housing by multiple contact points and by fasteners.
Advantageously, the present invention allows an electrical connector to have a small profile and overall size.
Also advantageously, the present invention allows an electrical connector in which a metal shroud remains securely fastened to an insulative housing and to a circuit board.
Also advantageously, the present invention allows a small electrical connector to maintain a stable electrical connection between an electrical device and a plug.
Also advantageously, the present invention allows a small ruggedized connector to be easily manufactured.
Therefore, it can be seen that these aspects of the present invention may be utilized to more reliably mount a small electrical connector to a circuit board or another body. These and other aspects, features and advantages of the present invention will be set forth in the description that follows and possible embodiments thereof, and by reference to the appended drawings and claims.